The polar cap heights (PCHs) plot suggestive of troposphere-stratosphere-troposphere strong #PolarVortex (PV) coupling event with tropospheric precursor this week & strong PV next week. If cycle is completed with #cold PCHs at the surface late Jan/early Feb put a fork in #winter! pic.twitter.com/Omdr0ueWj9

— Judah Cohen (@judah47) January 7, 2020